Sears David Bradley Trailers - Serial Numbers vs. Years

Sorry this is blurry
Sorry this is blurry. This is my DB trailer. I rescued Model 231-246, Serial # 3813 from the scrap heap. I purchased it for $200 from a gentleman who's wife wanted him to scrap it.

Hi all, created an account just for the Ben-Hur /David Bradley threads. I am picking up a Ben-Hur 22-46 and driving it back home to Colorado this week and just discovered what it was. Serial Number picture attached: